[erikzj]

'83 VT750
26,000 miles

I've noticed what seems to be clutch slippage when accelerating at highway speed. For example cruising at 70 when I need to pass so I pin the throttle and the tachometer jumps up 2k RPM almost instantly. Then the tach drops back and gradually climbs as the bike accelerates.

My question is, how can I narrow down the root cause?

• worn out clutch
• clutch needs adjustment
• oil

From reading Oilology I wonder if the Mobile 1 synthetic oil I'm using is just too slick and causing my clutch to slip. I only have about 1k miles on this oil change so I hate to waste it and change again so soon.

 

[shrinkwrap]

Are you using Mobil 1 automotive oil (energy conserving) or MC oil (non-EC)?

 

[95shadow1099]

Does the clutch burn/slip at lower speed? In first, gettin on it? It's hydraulic slave cyl, so besides bleeding system of ALL air, there's no "adjustment". Use 10-40 oil, synthetic or not...just NOT the energy conserving stuff.

 

[erikzj]

Are you using Mobil 1 automotive oil (energy conserving) or MC oil (non-EC)?

Does the clutch burn/slip at lower speed? In first, gettin on it? It's hydraulic slave cyl, so besides bleeding system of ALL air, there's no "adjustment". Use 10-40 oil, synthetic or not...just NOT the energy conserving stuff.

It's the automotive oil. A fellow biker recommended it so I tried it at my last oil change. When I get home I'll check the bottle for the term energy conserving.

 

[rrounds]

I don't know if your Honda has the same type of clutch springs that my '98 VT1100-T has but if it does you can put stiffer clutch springs in for as little as .75 cents.

Here is what I did
http://www.hondashadow.net/forum/72.../81380-no-more-slipping-clutch-cheap-way.html
2 1/2 years later and my clutch still holds better now than it did when my bike was new.

ROD

 

[93gc40]

Start with the oil. If it is M-1 automotive oil it could be the cause. If the fellow biker rides a NON Shadow, oil advise does not apply. If you are getting slippage in the lower gear or when cruising, look to the clutch. Always, Adjust first, if that don't work its the plates or springs.

 

[erikzj]

Start with the oil. If it is M-1 automotive oil it could be the cause. If the fellow biker rides a NON Shadow, oil advise does not apply. If you are getting slippage in the lower gear or when cruising, look to the clutch. Always, Adjust first, if that don't work its the plates or springs.

My buddy used to ride a VTX1800. He thought they were fairly analogous.

I've only noticed the slipping when trying to accelerate hard while already moving at highway speeds. Quite possibly I just don't notice it accelerating from a stop because my attention is on other vehicles at the intersection.

 

[93gc40]

My buddy used to ride a VTX1800. He thought they were fairly analogous.
.

Up to a point all bike are fairly analogous. As for the VTX, it is also not a Shadow. Heck I'm scepticle of Oil advise even if given by a Master Mechanic riding an identicle Shadow to my 1993 VT1100. I know what works for me, that is Standard Motorcycle rated oils or Deisel rated oils and SOME cheap NO Name Auto oils. Never found any benefit, to paying extra for Synth oil, in any of my vehicles. Every oil Rated for a Car or synthetic, I have tried, in my Shadow, had more slippage in the clutch.

 

[95shadow1099]

Springs are different than the 1100, it's a disk spring...not normal compression spring.

There's no adjustment in a hydraulic slave cyl operated clutch that I know of.

I guess it would be wrong to hold the front brake and rev/release clutch and see if tire burns...or clutch plates.... BUT THAT'S WHAT I DO/DID.

You probably need new disks and maybe plates. It's about a hundred bucks total for a cheap set...closer to 150 for the expensive...plates and disks.

Good luck figuring her out.

 

[cl65ame]

put the bike in 3rd gear. give it about 3000 rpm of throttle and release the clutch. if it stalls the clutch is fine.

Having said that. Check the oil type. Mobil 1 MOTORCYCLE oil not auto oil. Any oil with an MA rating is fine.

If it is a mechanical clutch (cable not hydraulic) then cjeck the play on the lever. if its correct then the clutch is worn out. you can try new springs but either way you are removing the clutch to find out.

Remove the clutch discs and measure the thickness. if beyond limits replace them.

Oil is the only thing you can check without taking the cover off. Once you have eliminated it as the problem remove the clutch cover and inspect the clutch. It is the proper way to do it.

 

[Frogman172]

I think some of the guys nailed it. Energy Conserving Oil? See if your bike allows for that automotive oil. If not, I think you may have just made life just a tad bit difficult. If you get that out of your engine and replace it the damage may have already been done. You can replace the oil and try a cheap method with replacing the springs. I did that and it didnt work. I went into my clutch again and just replaced all the friction plates. I wrote a how to or DIY on this a while back. If you want you can take a look at this.https://picasaweb.google.com/Frogman172/NewClutch?authuser=0&feat=directlinkJust order your friction plates and take care of it yourself. I assume (ass-u-and-me) the clutch on the Hondas are similar. I replaced my friction plates because my clutch was slipping just like yours. I would hit a bump or jam the throttle and it would slip passing cars. Not good. On the Honda Aero 1100 they tend to just give up. Not that uncommon. But you can fix your own clutch with the DIY I posted between $40-$270. I did if for $175. Did three different bikes of them the same way. Made a world of difference. Let me know if you need help. You can call me or email me if you or anyone else needs to.